carb idle circuit

on my kz1000, i can turn the #1 carb idle air screw all the way in and the idle doesn't change on the engine.
i take the carbs off and spray cleaner thru the idle circuit and no clogs are noticed. what else would cause this problem? i've cleaned out every port i can see on these carbs. am i missing something? at highway speeds these carbs work great. i only have problems at low speeds putting around. thanks for the help.

Playing with idle air screw may/will not change idle speed. What mods done to bike (intake, exhaust or internals)? Need more info on syptoms and engine state of tune.

i believe it is stock, except for the 4 into 1 open exhaust and the k & n filters.. if i screw in #4 carb, the idle drops and it sputters and dies. i screw in #1 and nothing changes. i've cleaned it out (at least i think i did). i can spray carb cleaner thru the ports with no obstruction. i do not know what else would cause this. could it be partially clogged?

i think i found the problem. i am using emgo filters..i saw a thread a while back showing that the emgo's have a fat inner lip that can obstruct the ports...i believe this is what is happening to me.